I was thinking that one under appreciated aspect of SSDs are their longevity. Even if SSDs don't get as cheap as HDDs to purchase, their amortized cost will be less because they live so much longer. I could see a scenario (for consumer level usage) where SSDs are passed down to children, grandchildren, etc. Or are we talking uncharted territory here?

I think a heavily used SSD is suppose to last between 6-8 years. With the amount of failure rates floating around for certain drives I'm sure their life expectancy is much lower. However let's say it hit the top end of the realm and made it to 10-12 years, I doubt it would be worthwhile at all to pass onto your Children. By that time it would be archaic technology (look at anything from 10 years ago compared to today) as well as the interface could very well be outdated.

Ten years ago from Right Now, a decent mid-range computer was a 2.2GHz Pentium 4 with 2GB of RAM, an 80GB HDD, and a CD-R/W drive. The now-ubiquitous SD card had been commercially available at 32 and 64MB (with an "M") capacities for less than two years and higher-capacity cards were just starting to become available at affordable prices, and a decent USB flash drive was around 256MB (also with an "M"). Many computers still had 3.5" floppy drives, although by then, these were rarely used for anything other boot-up troubleshooting.

Ten years before that, a decent mid-range computer was a 486/DX-33MHz (with an "M") and although it may have included a CD-ROM, it definitely included a 3.5" floppy disk drive and it may have included a 5.25" disk drive as well.

Ten years before that, the original Apple Macintosh did not yet exist. A 5.25" floppy stored 360kB (with a "k") of data, and many computers had two such drives -- one to boot the OS and another for data and programs.

I can't imagine why even my children, let alone grandchildren, would have much interest in any SSD I own now. Ten years out and it will be small, slow, and tired. Twenty years out and it will be a legacy device. Thirty years out and they won't have anything to plug it into.

If I had a 5-year-old hard drive with normal usage patterns, I'd be more nervous than if I had an ssd of the same vintage. It might save me some money and headache if I owned the ssd, and in addition the ssd would still probably be "fast enough" for the computer it was in, while a traditional hard drive isn't "fast enough" the day the computer comes off the assembly line (once you're used to the speed of an ssd).

Perhaps that was more his point. You're right that it's probably not something that you're going to move from an old computer to a new one, but it might be the difference between buying a new computer sooner because you're not confident in the hdd, versus holding onto that computer for a few more years.

Having said that, my build cycle for computers is probably less than two years on average, so it's not a problem I run into much personally.

Intel released some results of a test it did for the, I believe, consumer SSD's and the end result is, don't worry. The test showed that you would have to write a TB of data to the drive, EVERY day for something like 5 years.

For household use, the SSD will last a very long till the point where the capacity just isn't worth keeping around.

The longevity of the SSD might suffer depending on how aggressive its TRIM implementation is. And all SSDs are not created equal. Some controller designs have bugs. Case in point is my Corsair Force series 60gb drive. SMART data showed it had 100% life left. But one day, it just screwed up on its own. Now I cant write data to it for more than 5 minutes. It then freezes up and I have to remove the power plug and turn it back on. Which means it's a useless piece of junk now. I wouldnt recommend buying an SSD with a Sandforce controller after this experience. Go with Intel or Samsung.

Just because it has no moving parts doesn't mean a SSD can't fail or wear out.

Flash cells used in typical consumer SSDs can only be written a few thousand times before they start to degrade and lose their ability to retain data. Wear leveling and error correction algorithms make the effective durability of the drive a lot better than this, but it still has a finite lifetime. A heavily used SSD is probably no more reliable over the long term than a mechanical HDD.

It is also likely that mechanical HDDs have better long-term archival data integrity, as long as they are stored somewhere reasonably cool and dry. Flash memory chips use tiny amounts of stored electrical charge to record the bits; this charge can eventually leak away, corrupting the data. The leakage issue is significantly worse for MLC flash (the type of flash used in all consumer SSDs), and gets worse with increasing temperature. The more reliable SLC flash is typically reserved for high-end enterprise, industrial, and military applications, where the customer is willing to pay a substantial price premium.

Even if SSDs were as durable as you seem to think they are, what makes you think that the computing devices in use several decades from now will even have SATA ports on them? Storage capacities will also have increased by several orders of magnitude.

From a reliability, compatibility, and capacity standpoint, passing down one of today's SSDs to your grandkids a quarter century from now will probably make about as much sense as your parents giving you a box of old 5-1/4" floppy disks today.

The years just pass like trains. I wave, but they don't slow down.-- Steven Wilson

just brew it! wrote:Just because it has no moving parts doesn't mean a SSD can't fail or wear out.

Flash cells used in typical consumer SSDs can only be written a few thousand times before they start to degrade and lose their ability to retain data. Wear leveling and error correction algorithms make the effective durability of the drive a lot better than this, but it still has a finite lifetime. A heavily used SSD is probably no more reliable over the long term than a mechanical HDD.

I agree, but the question is how many people "heavily use" their SSD? Say you can write the cells 5000 times before they become useless; for a 128GB drive, that would be 640,000GB written to it, or 100GB per day for 17 years. I think it's safe to assume virtually no consumer is going to be writing that much data to a drive.

I just can't imagine the write cycles being an issue for 99.9% of consumers. Of course there are other things that could go wrong with an SSD though, so just because the flash memory is reliable doesn't mean the overall drive will be (just look at all the Sandforce-1200 controller problems). We have seen a trend of smaller fab processes reducing the number of write cycles though, so perhaps it could become an issue as we continue shrinking the NAND flash.

just brew it! wrote:Even if SSDs were as durable as you seem to think they are, what makes you think that the computing devices in use several decades from now will even have SATA ports on them? Storage capacities will also have increased by several orders of magnitude..

Yep. Even if SSDs somehow never fail I just find it very unlikely that we will be using SATA 20 years from now, let alone long enough to pass it to your grandchildren. We are already bumping up against the limits of the current SATA revision with SSDs. They can probably increase the speeds of SATA again but eventually you have to think they'll reach a limit.

just brew it! wrote:From a reliability, compatibility, and capacity standpoint, passing down one of today's SSDs to your grandkids a quarter century from now will probably make about as much sense as your parents giving you a box of old 5-1/4" floppy disks today.

Yep, I think the best way to pass your data down to your kids/grandkids is just to continually copy that data to the latest technology, rather than trying to "time capsule" it in storage for 50 years. As internet speeds increase keeping your data on "the cloud" will become more practical as well, although that has even more reliability concerns than local storage.

Seriously, everybody's comments are well argued, rational, and correct. But I guess I left out one crucial (M4 pun intended) assumption: that Flash memory well be as good as it gets. Hasn't the entire history of non-volatile storage been primarily about capacity? I realize that going from Floppy to HDDs was an incredible speed jump. But hasn't HDDs now maxed out at around 10,000 rpms. And SSD are easily an order of magnitude faster. But does NAND memory have much headroom? Haven't we pretty much maxed out on SSD read/write speeds? Aren't we now at a speed plateau where just capacity is being noticeably increased? Maybe there is something in the labs that I don't know of.

With this assumption (and I hope I am wrong here): that HDDs and SSD are as good as it gets. Then wont SSDs be the only non-volatile storage that consumers (house-holds) will need/use? And HDDs will only be used by the cloud were capacity will always be king.

From this perspective, is where I drew my hypothetical. And from there is where I see people keeping their SSD for a much longer time than as been the historical case for non-volatile storage.

WhatMeWorry wrote:With this assumption (and I hope I am wrong here): that HDDs and SSD are as good as it gets. Then wont SSDs be the only non-volatile storage that consumers (house-holds) will need/use? And HDDs will only be used by the cloud were capacity will always be king.

Every technology has been "as good as it gets," until something faster comes along and upsets the apple cart. For example Flash memory was slow, expensive, and low capacity...until it wasn't. The storage revolution in SSDs has only been going down for about four years and it is still a very nascent technology. Before that, 10k RPM hard drives with large caches were the cream and enthusiasts paid a hefty premium to get them, and the only alternative was an expansion card packed with SDRAM and a backup battery to survive momentary power glitches.

In the 15 years that I've been rolling my own PC hardware, I remember having a few "wow" moments where I was working with hardware and software that seemed like it had achieved some stunning new plateau of performance and might not be superseded for a very long time. I have variously sold away, given away, and thrown away most of that hardware in the years since.

"Say you can write the cells 5000 times before they become useless; for a 128GB drive, that would be 640,000GB written to it, or 100GB per day for 17 years"

Doesn't work that way. Only the unused space can be used to spread write data.

So if you have a 64GB drive and its 80% full, that mean only 12GB is directly available if the cell are rate at 5000 refresh. Thats 60,000GB, or 32GB a day on average for 5 years.And BTW, this is conservative because entire block need refresh even if its a partial write. so for small file you can half that number.

If you have a small SSD that is almost full and do allot of IO... the life of the drive might not be as long as you wished.(Smart controller might do data relocation, but its unclear if this does happen)

sschaem wrote:"Say you can write the cells 5000 times before they become useless; for a 128GB drive, that would be 640,000GB written to it, or 100GB per day for 17 years"

Doesn't work that way. Only the unused space can be used to spread write data.

So if you have a 64GB drive and its 80% full, that mean only 12GB is directly available if the cell are rate at 5000 refresh. Thats 60,000GB, or 32GB a day on average for 5 years.And BTW, this is conservative because entire block need refresh even if its a partial write. so for small file you can half that number.

If you have a small SSD that is almost full and do allot of IO... the life of the drive might not be as long as you wished.(Smart controller might do data relocation, but its unclear if this does happen)

Good points but even 32GB is way more than the average person writes in a day. I've monitored my writes with Procmon and I only write about 1-2GB per day (unless I install a game or something) to my SSD. Reads reduce the life of the flash too, but they have a much smaller impact on durability than writes.

Admittedly I do my video encoding on my spinning disk, but most people don't do video encoding at all. If you are doing a lot of video encoding/editing on a SSD you'd probably want a lot more than 64GB to work with anyway. You can't fit much HD video (especially uncompressed) on 64GB

I think the assumption here is that SSDs are something special, and they're really not. Regardless of how good they are now, the industry will continue to innovate and in 10 years our current SSDs will be clunky and either thrown away or stored in a box somewhere, never to be used.

absurdity wrote:I think the assumption here is that SSDs are something special, and they're really not. Regardless of how good they are now, the industry will continue to innovate and in 10 years our current SSDs will be clunky and either thrown away or stored in a box somewhere, never to be used.

Hell, in 10 years we'll be thinking "How did we manage with these things?" We'll keep thinking of the days we used our slow, low capacity, and wearing SSDs.

absurdity wrote:I think the assumption here is that SSDs are something special, and they're really not. Regardless of how good they are now, the industry will continue to innovate and in 10 years our current SSDs will be clunky and either thrown away or stored in a box somewhere, never to be used.

Hell, in 10 years we'll be thinking "How did we manage with these things?" We'll keep thinking of the days we used our slow, low capacity, and wearing SSDs.

In 10 years we'll hopefully have some of the things that were supposed to come out in 5-7 years 10 years ago

sschaem wrote:Only the unused space can be used to spread write data. So if you have a 64GB drive and its 80% full, that mean only 12GB is directly available if the cell are rate at 5000 refresh. Thats 60,000GB, or 32GB a day on average for 5 years.

sschaem wrote:Only the unused space can be used to spread write data. So if you have a 64GB drive and its 80% full, that mean only 12GB is directly available if the cell are rate at 5000 refresh. Thats 60,000GB, or 32GB a day on average for 5 years.

Are you taking wear-leveling into account? Doesn't seem like you are.

I assume that all drive do dynamic wear leveling, but do you know what drive do static wear leveling ?

sschaem wrote:I assume that all drive do dynamic wear leveling, but do you know what drive do static wear leveling ?

I know the high reliability (designed for industrial/military applications) devices we use at work do. I don't know for certain how common this is for consumer drives; but given that the durability of the individual flash cells has actually gotten *worse* over the past few years (due to higher density cells and the move to TLC), I would expect that all of the major vendors must be using some sort of static wear leveling (and very aggressive ECC as well) to get reasonable MTBFs. At least one controller vendor (SandForce) also does on-the-fly compression of the data being written to reduce the number of writes to the physical flash cells.

The years just pass like trains. I wave, but they don't slow down.-- Steven Wilson

For my personal system, there's no way it averages 32GB / day of writes. My machine is asleep most of the time. If I had to guess at a long term average for my machine it would be well under 5GB per day, I think. I'd want a 256GB drive for myself too - those are getting very affordable. A 256GB drive would give me at least 100GB of spare area. Combine my average writes per day with the size of spare area I assume I'll have and I figure a 5000 writes per cell drive would last me a very, very long time. Point being, take a look at your personal usage and assumed spare area.

Microsoft wrote:In looking at telemetry data from thousands of traces and focusing on pagefile reads and writes, we find that•Pagefile.sys reads outnumber pagefile.sys writes by about 40 to 1, •Pagefile.sys read sizes are typically quite small, with 67% less than or equal to 4 KB, and 88% less than 16 KB.•Pagefile.sys writes are relatively large, with 62% greater than or equal to 128 KB and 45% being exactly 1 MB in size.

"Welcome back my friends to the show that never ends. We're so glad you could attend. Come inside! Come inside!"

tldr: high performance SSD, Intel eMLC flash 10,000 writes per cell, $1/GB for the 240GB drive, 5 year warranty. This drive should last a good long time depending on your average writes per day and your data footprint. In terms of passing a decade-old drive on to someone else, that's something I'd argue should not be a realistic metric for ANY computer part, to be honest. But this drive probably could last for a decade for anyone with a drive usage profile like mine.

So here's some real data. This is my OCZ Vertex 2 running on my main Ubuntu Linux box. Before now I used this box at work as a build server, but now it is my home desktop. It's the only drive in the box so everything (i.e. swap as well) goes on to the drive. I'm not a gamer, but the builds were ridiculously huge, hence the high read and write values.

It's a 120GB drive that's only 35% used and I bought it when the Vertex 2 first came out. Those figures are peanuts for big media drives, but for the size of SSD and how bad the Vertex 2 is meant to be, it's holding up fine for me. If others have figures, let's see them.